In the automotive industry it is increasingly desired to provide controllable and/or dynamic light distribution using lighting devices. For example, certain areas of the high beam function shall be dimmed when a vehicle is driving ahead in the light [cone] distributed or a pedestrian walks into it. In order to realize such controlled light distributions the lighting devices installed increasingly comprise a plurality of individually controlled light sources, particularly light diodes. The partial light beams emitted by the individual light sources are combined in a subsequent light forming optic unit and shaped such that the desired light distribution is provided. Here it is problematic that for example light sources arranged like a matrix show a lateral distance from each other not optimal according to aspects of lighting technology. Lighting devices with a plurality of individual light diodes in the SMD design sometimes show excessive lateral distances of the light sources. In this case light spots (light gaps), i.e. sections not or insufficiently lit, which are disturbing and should be avoided for safety reasons, may form in the light distribution.
In order to achieve homogenous light distribution even in disadvantageously distanced light sources and thus avoid light spots the partial light beams emitted by the individual light sources are widened in proximity to the light source. For example, it is known from DE 10 2008 005 488 A1 that a transparent, microstructured thin plate is provided between the light sources arranged in a common lighting level and an optic unit provided in the light path in front of the light sources. Using this plate the partial light beams of the individual light sources are widened. By the widening of the individual partial light beam a homogenous light distribution can develop, at least largely free from lighting spots. For this purpose, the transparent plate comprises a grooved and/or corrugated surface, for example. Although the use of the transparent plate has generally proven to be valuable, an individual widening of individual partial light beams can only occur to a limited extend when using a single common plate.
Another option to form individual partial light beams near the light sources is known from DE 10 2008 013 603 A1, DE 10 2008 044 967 A1, and DE 10 2009 053 581 B3. Here, an optic unit with a plurality of individual optic elements, arranged like a matrix, is provided near the light sources, with one optic element each being precisely allocated to one single light source. Accordingly, the partial light beam emitted by the individual light source is essentially formed only in the optic element allocated to the light source. The individual optic elements comprise a cross section widening over the course of the beam, for example a contour like a frustum and/or truncated pyramid. Accordingly they are expensive in their production. Furthermore, the optic elements to form the light are not or only insufficiently suitable for widening a partial light beam and for realizing a homogenous light distribution due to their design.